There is, what appears to be a bug in the version of Safari that comes with iOS 14+. This bug impacts other applications that also use Activity Extensions.
The bug causes the “Send to ClipDish” button to intermittently disappear from the list of available actions.
If this happens, closing the Activity View and tapping the Share button again should correct the issue.
We are working on an update to ClipDish that will use a different method for clipping that should get around the issue while we wait for Apple to fix Safari.